Motorized wheel chair steered by driving



H; ROSENTHAL. ET AL I MOTORIZED WHEEL CHAIR s'rEEREn BY DRIVING I): SheetE-She'qt 1 Filed Dec. 23, 1954 INEN 2,798,565 MOTORIZED WHEEL'QI-XAIR STEERED BY DRIVING Filed D80. 23. 19'54 15957 H. kosEN'rHAL Er AL Sheets-Sheet 2 r V 1 W 1 f?? y 9,1957 -H. ROSENTHAL El AL 2,798,565

" MOTORIZED WHEEL CHAIR sTEEREDpY DRIVING 3 Sheets-Sheet 5 Flled Dec 23 1954 United States Patent MOTORIZED WHEEL CHAIR STEERED BY DRIVING Harry Rosenthal and George E. Slaboch, Chicago, 115.; said Slaboch assignor to said Rosenthal Application December 23, 1954, Serial No. 477,273

9 Claims. (Cl. 180-65) This invention relates generally to motorized wheel chairs for invalids and more particularly to improved electric driving apparatus for such chairs.

Electrically driven wheel chairs for use by physically handicapped persons have been known in the prior art, but the motor driving devices for such wheel chairs have been of rather complex construction and of a type not easily installed on a given wheel chair. Furthermore, there is a need to improve the motorized wheelchairs of the prior art to render them more practical so that they are easily operable by partially incapacitated persons by means of a minimum number of simple controls which provide sufiicient regulation for maneuvering in the close quarters frequently encountered as, for example, in the home.

Accordingly, it is an object of the present invention to provide electric motor driving apparatus for a wheel chair which is of simple and inexpensive construction.

Another object is to provide an improved motor driving attachment for an invalids wheel chair which attachment may be easily installed thereon.

Still another object of the invention is to provide an improved electrically driven wheel chair which is operable for forward and reverse travel and which may turn within a very small radius.

Yet another object of the invention is to provide a highly maneuverable motor driven wheel chair having a minimum number of easily operable controls which are arranged to prevent inadvertent damage to the system if operated improperly.

A feature is the provision of an improved motor driven wheel chair utilizing an electric motor drive for each of two wheels thereof and an energizing circuit for the motors having switches to selectively operate the individual motors in forward and reverse rotation for maneuvering the wheel chair.

Another feature of this invention is the provision of an attachment for a standard wheel chair for converting the same to a motorized chair in which the various parts can be easily attached to the chair without any modification thereof.

A further feature of the invention is the provision of an improved motor driving attachment for a wheel chair including a pair of separately operable electric motors pivotally supported on the frame of a wheel chair, with the motors having drive drums individually engageable and disengageable with a pair of wheels of the wheel chair upon pivotal movement about the shaft.

Still another feature of the invention is the provision of an improved wheel chair having a four position switch device to operate selectively a pair of electric driving motors for complete maneuverability of the chair including forward and reverse travel as well as turning of comparatively wide radius, and turning of very small radius.

Further objects, features and the attending advantages of the invention will be apparent upon consideration of the following description when taken in conjunction with the accompanying drawing in which:

2,7 98,565 Patented July 9, 1957 Fig. l is a perspective view of a wheel chair with the motor driving apparatus of the present invention installed therein;

Fig. 2 is a side elevational view of the chair of Fig. 1;

Fig. 3 is a top plan view of a portion of the wheel chair of Fig. 2;

Fig. 4 is a schematic diagram of the wiring circuit used; and

Figs. 5 to 8 illustrate a second embodiment of the invention.

The motor driving apparatus of the present invention includes a pair of reversible electric motors pivotally supported by the frame of a wheel chair. A driven drum associated with each motor is frictionally engageable with the periphery of each of two wheels of the chair. The motors may be pivoted to a position of disengagement with the wheels of the chair should this be desirable. A battery and a control circuit supply power to the motors. A control head with four individual switches included in the control circuit permit selective operation of each of these motors in forward and reverse directions. Therefore, complete maneuverability of the wheel chair is effected by operation of these switches and energization of the motors singly and in combination for travelling forward, backward, turning sharply, or turning less sharply. The motors, battery and frame therefor, and the control head form assemblies which may be easily attached to the frame of a standard wheel chair to convert the same to a motorized chair.

Referring now to the drawings, Figs. 1-3 show an invalids wheel chair which may be of standard construction including a frame 10, a seat 12, a back 14 and foot rests 15. The frame 10 is provided with main driving wheels 16 and 18, one being disposed on either side of the frame, both wheels being rotatably mounted on axles 20. Smaller front wheels 25 are pivotally secured to the frame to provide a balanced structure. Vertical frame members 27 and 28 extend upwardly from lower frame members 22 and 23 and these vertical frame members serve to support the seat 12 and the back 14. Suitable handle grips 30 are secured to the ends of the vertical frame members 28 in order that the wheel chair may be conveniently moved by an attendant. Arm rests 32 are also provided for the seat 12 and are supported by other members of the frame.

The electric motor driving apparatus for propelling the wheel chair thus described includes reversible electric motors 40 and 41 which are mounted upon their respective support brackets 44 and 45. These brackets are pivotally secured to an axle 47 which is mounted. by means of sleeves 48 and 49 respectively disposed upon the lower frame members 22 and 23. The motors 40 and 41 also include gear reduction mechanisms 54 and 55 which operate the driving drums 58 and 59 respec tively. It is also possible to mount the motors separately in pivotal relation on frame members 22 and 23 instead of using axle 47 which extends across the frame. Such a construction is illustrated in Figs. 5, 6, and 7, and is described more in detail hereafter. Such a modification may be desirable in the case of a folding wheel chair so that the motors could remain mounted when the chair is folded.

A pair of clutch levers 62 extend rearward from the support brackets 44 and 45 and it is apparent that by raising the levers 62 and supporting them upon an inner extension 64 of the axle 20 the driving drums 58 and 59 may be supported as shown in Figs. 2 and 3. However, the levers 62 may be removed from their support upon the inward projections 64 by bending them slightly inward to bring the drums 58 and 59 into contact with the peripheries of the driving wheels 16 and 18. Tension springs extending between the levers 62 and the respective'lower frame members 22 and 23 serve to maintain the driving drums in contact with the driving wheels as shown by the dotted line portion of the drawing of Fig. 2. Therefore, a simple clutch mechanism has been provided in order to place the motors in an operative position or to disengage them which may be desirable, for example, when an attendant is to push the wheel chair.

The reversible electric motors 40 and 41 are energized by means of the storage battery 75 supported on brackets 76, the power from which battery is applied to the motors by means of cable 77 connected to the battery and the motors and circuit elements contained in the control head or box 80 disposed adjacent an arm rest. In the illustrated form of the control box it is possible to propel the wheel chair in a forward direction by manipulation of push-type switches 81 and 82 while the chair may be moved backwards by manipulation of push-type switches 83 and 84. These operations drive the electric motors 4 and 4-1 respectively in what may be termed forward and reverse rotation. If it is desired to turn the wheel chair in a small space, switches 82 and 84 may be operated in order to drive the motor 41 in a forward direction and the motor in a backward direction thus rotating the chair about an axis midway between the driving wheels 16 and 18. Similarly, a sharp turn to the left may be effected by operating switches 81 and 83 in which case the motor 40 is driven in a forward direction and motor 41 is driven in a backward direction thereby turning the wheel chair to the left. It is apparent that by such maneuvering the entire chair may be turned in a minimum of space which, as has been pointed out, is frequently desirable in the crowded conditions often found in such places as the home.

It is also possible, of course, to turn the chair in a wider radius by operating only one of the switches in which case the chair would pivot, about one of the driving wheels while being driven by the other driving wheel. That is, by operation of switch 81 alone, motor 40 will be energized to drive wheel 16 forward with wheel 18 remaining stationary, or by operating switch 82 motor 41 will be energized to drive wheel 18 in a forward direction while wheel 16 remains stationary. Thus, by manipulation of the switch buttons, complete maneuverability is possible and forward and reverse motion is available in addition to a choice of turn radii.

The control circuit for energizing the motors 40 and 41 is shown in Fig. 4-. Thestorage battery 75 is coupled to a fuse 90 and on-off switch 91 to stationary contacts 9497 associated respectively with switches 84, 81, 82 and 83. In the unoperated positions of these switches the stationary contacts 94 and 95 are coupled together through a rheostat 100 and the contacts 96 and 97 are coupled together through a rheostat 101. The stationary contacts 104107 are engaged in the operated positions of the respective switches 84, 81, 82 and 83. The reversible motor 40 has a pair of terminals coupled across the contacts 104 and 105 and the motor 41 has a pair of connections coupled across the contacts 106 and 107. The return connectionis made from each motor to the battery 75 and the motors are constructed so that energization of the motors through contacts 104 and 107 drives each in a reverse direction and energization of them through contacts 105 and 106 drives each of them in a forward direction.

It is apparent that by operation of switch 84, power will be supplied to reversible motor 40 through rheostat 100 and stationary contact 95 thereby driving this motor in a reverse direction. Similarly, operation of switch 81 Supplies power to the motor 40 to stationary contact 105, rheostat 100 and stationary contact 94 thus driving the motor in a forward direction. In a corresponding manner, operation of switch 83 drives motor 41 in a reverse direction and operation of switch 82 drives this motor in a forward direction. Main switch 91 may be disposed in any convenient position (not shown) on COIItIQl b0 80. The rheostats and 101 are utilized to balance the system in order that both motors will drive the chair with equal torque so that when both forward buttons or both reverse buttons are operated, the wheel chair will travel in a straight line. The rheostats 100 and 101 may also be used to adjust the speed of the chair in forward and reverse directions. Alternatively, a separate rheostat 102 may be provided in the common lead from battery 75 to the motors 40 and 41 to simultaneously control the speed of both motors. When the rheostat 102 is used for speed control, rheostats 100 and 101 could be quite small for balancing and when once set would not need to be changed.

In Figs. 5 to 8 inclusive, there is shown a second embodiment of the invention wherein the motorized unit is applied to a Wheel chair of the folding type. In such a chair, side frame 110 and 111 have main driving wheels 112 and pivotal front wheels 113 secured thereto. The two side frames are interconnected for collapsing movement with respect to each other by a cross bar pivoting arrangement formed by main members 115, 116, 117 and 118. These members, in addition to connecting the side frames, support the seat 120. The cross bars are connected to the side frames at the bottom thereof, and also by arms 121, 122, 123 and a fourth arm not shown. A comparison of Figs. 6 and 7 illustrates the manner in which the chair folds, but it is to be pointed out that this is a standard construction and is shown only to illustrate the application of the invention.

In the embodiment of Figs. 5 to 8 each of the motors 125 is mounted on a supporting plate 126 pivotally connected at 127 to the member 128 of the side frame. The plate 126 is pivoted so that the driving drum 129 connected to motor 125 through speed reducing gears may be selectively held in engagement with the wheel 112. Spring 130 connected between the plate 126 and a bracket secured to the same bolt as arm 122 holds the driving drum 129 normally in engagement with the wheel 112. A control arm 131 extending upwardly from the plate 126 operates in a bracket 132 to hold the motor 125 in a position so that the driving drum 129 is clear of the wheel 112. This is illustrated in Fig. 8 which is a fragmentary top view showing the bracket 132 and the arm 131. The arm 131 is shown held in the notch 132' so that the drum is out of engagement, but may be released from the notch so that the spring 130 holds the drum in driving position.

It is to be noted that the pivot 127 and the bracket 132 may be parts of a standard wheel chair, being normally used for a brake therefor. Accordingly, the brake may be removed and the motor mounting plate installed without making any other changes on the frame. The brake is, of course, not required when a motor is used, since the speed reducing gears of the motor prevents rotation of the driving drum by the wheel so that driving mechanism forms a brake.

The position of the control arms 131 is such that a person in the chair may be able to operate the same to engage and disengage the motor. This provides an advantage over the structure shown in Figs. 1 to 3 wherein the motor control levels are inaccessible to a person in the chair.

The control mechanism for the system of Figs. 5 to 8 may be generally the same as in that of Figs. 1 to 3. The control box 135 in addition to including the push button switches 136 at the top, which directly control the operation may also include one or more rheostats 137. The control circuit of Fig. 4 may be used, with the push buttons 136 operating in the same manner as the push buttons 81-84 of the first embodiment. The rheostats 137 may be used in the control system as shown in Fig. 4, being the rheostats 100 and 101, also, if a single rheostat 102 is used for speed control, this rheostat may be providedon the box 135 f0r access by the person in the chair. In such case, the rheostats 100 and 101 can be provided inside the control box and need not be directly accessible.

To permit folding of the chair, a removable battery plate 140 is provided. This plate provides a flat support on which the battery rests, with curved end portions 141 and 142 which fit over the bottom portion of the side frames at the rear thereof. A bail 143 may also be provided to permit easy removal of the battery. Projection 145 may be provided at the back of the chair frames so that the battery plate will not slide off the chair.

It will be noted that the position of the motors on the side frame is such that the chair can be telescoped almost to the same extent as when the motor driving device is not provided thereon. This permits the chair to be folded for transportation, storage and the like. The motor driving device does not add substantial weight except for the battery and this may be handled separately.

It is obvious, of course, that other mounting positions may be used for the control boxes 80 and 135 in order that the switches may be operated by a foot or ditferent hand of the individual and that convenient lever devices may be provided for operation of these switches in any given case.

The invention provides, therefore, motor driving apparatus for a wheel chair which provides great maneuverability of the chair, including travel in any desired direction in addition to turning of the chair in the smallest possible radius. The apparatus may be provided initially as an integral part of the chair or may be installed as an attachment at a later time. The simplicity of attachment necessitates only a support for the battery, attachment of the control box, attachment of springs, and attachment of the motor support. All these attachments may be provided without modification of stand ard chairs as has been described. Accordingly, the invention comprises a highly satisfactory motor driving attachment for an invalids wheel chair which is easily installed and of simple and inexpensive construction.

We claim:

1. A motor propelling device for an invalids chair of the type having a frame structure for supporting a person and a plurality of wheels at least two of which are disposed on opposite sides of the frame to constitute driving wheels, said device including in combination, a pair of reversible electric motor means individually associated with the driving wheels and each having an associated drive drum rotatable thereby, first and second support means each including pivotal means for mounting the same on the opposite sides of the frame structure adjacent the driving wheels, with said support means being at least partially within the space defined by the frame structure, said pair of motor means being individually mounted on said support means with the drive drum of each motor means in a common plane with the associated driving wheel, first and second manually operated control means individually associated with said support means to provide pivotal movement of said support means, said drive drums individually engaging said driving wheels upon operation of said control means to provide pivotal movement of the associated support means to a first position and being disengaged from the same upon operation of said control means to provide pivotal movement of the associated support means to a second position, said con trol means including spring means for biasing said support means in said first position, said control means including means operative to hold said support means in said second position, and a power supply circuit coupled to said motor means, said power supply circuit including a plurality of switch devices for individually energizing said pair of motor means to rotate the respective drive drums selectively in forward and reverse directions, so that the invalids chair may be driven in a chosen direction by the rotation of said drive drums in the same rotational directions respectively and may be turned by non-uniform rotation of said drive drums.

2. Electrical driving apparatus for an invalids chair of the folding type having a frame structure with a pair of spaced parallel side sections connected for 'movement toward each other and each supporting a comparatively large driving wheel, the frame further including pivotally supported front wheels and a chair portion for a user, the electrical driving apparatus for such a chair including in combination, first and second support means each including pivotal means for mounting the same on the side sections of the frame structure adjacent the drive wheels and at least partially within the space defined by the side sections, a pair of reversible electric motor means individually mounted on said support means and each having a drive drum rotatably driven thereby and lying in a common plane with the associated driving wheel, each of said support means including control means for controlling the position of said support means about said pivotal means, said control means each moving the corresponding support means to a first position in which said drive drum of a motor means supported thereon engages the associated driving wheel for rotating the same upon energization of the associated motor means, said control means each moving the corresponding support means to a second position in which said drive drum of the motor means supported thereon is disengaged from the associated driving wheel for manual propulsion of the chair, battery supportingmeans removably positioned on the frame structure, and a power supply circuit for connecting said pair of motor means to a battery on said supporting means, said power supply circuit including switch means for individually energizing each of said motor means to & rotate the respective drive drums selectively in forward and reverse directions, so that the invalids chair may be driven in forward and reverse directions by the rotation of said drums in the same directions respectively and may be turned by non-uniform rotation of said drums.

3. A motorized propelling device for attachment to a wheel chair of the type having a frame structure for supporting a person, and which includes a pair of driving wheels mounted independently of one another on opposite sides of the frame structure, said device including in combination, a pair of reversible electric motor means individually associated with the driving wheels and each having a drive drum rotatable thereby and lying in a common plane with the corresponding driving wheel, a

pair of support means one being on each side of the frame structure adjacent the driving wheel on such side, each of said support means mounting one of said motor means thereon, means pivotally connecting said support means on the frame structure at least partially within the space defined by the frame structure, each of said support means including control means for controlling the position of said support means about its pivotal connection to said frame, whereby each of said drive drums engages independently the associated driving wheel upon movement of said support means to a first position and disengages the same upon movement of said support means to a second position for manual propulsion of the chair, a battery, carrying means for said battery carried by the frame structure, and a power supply circuit for coupling said pair of motor means to said battery, said power supply circuit including switch means for supplying power to each of said motor means independently to cause rotation of the respective drive drums in forward and reverse directions, whereby the wheel chair may be driven in a straight line by the rotation of said drive drums in the same rotational directions respectively and may be turned by selective rotation of said drive drums.

4. A motorized propelling device in accordance with claim 3 wherein each of said control means includes a spring connected to the associated support means for holding the same in the first position with the drive drum of the motor means mounted on said support means being held in frictional engagementrwith the associated driving wheel. 7 Y i 5. A' motorized propelling device in accordance with claim 3 wherein each of said control means includes spring means connected to the associated support means for holding the same in the first position so that the drive drum of the motor means mounted on said support means frictionally engages the associated driving wheel, each control means also including lever means for holding the associated support means in said second position so that the drive drum is disengaged from the associated driving wheel.

6. A motorized propelling device in accordance with claim 3 wherein each of said motor means includes a first terminal energization of which causes rotation of the drive drum thereof in a first direction and a second terminal energization of which rotates the drive drum thereof in a reverse direction, and wherein said switch means includes a pair of first switches individually coupled to said first terminals of said motor means and a pair of second switches individually coupled to said second terminals of said motor means, whereby simultaneous action of said switches of said first pair energizes said motor means to cause movement of said chair in a forward direction, simultaneous operation of said switches of said second pair causes operation of said chair in a reverse direction, and individual operaton of said switches causes operation of said motor means to turn the chair.

7. A motorized propelling device in accordance with claim 3 wherein each of said motor means includes a first terminal energization of which causes rotation of the drive drum thereof in a first direction and a second terminal energization of which drives the drive drum thereof in a reverse direction, wherein said switch means includes a pair of first switches individually coupled to said first terminals of said motor means and a pair of second switches individually coupled to said second terminals of said motor means, and including circuit means interconnecting said switches and said motor means including variable resistor means, with said first and second switches coupled to each of said motor means being mutually interconnected through said resistor means so that said resistor means controls the amount of power furnished to each motor means and only one of said terminals of each motor means may be energized at a particular time.

8. A motorized propelling device for attachment to a wheel chair of the type having a frame structure for supporting a person, and which includes right and left driving wheels mounted independently of one another on opposite sides of the frame structure, said device including in combination, a pair of reversible electric motor means individually associated with the driving wheels and each having a drive drum rotatable thereby and lying in a common plane with the corresponding driving wheel, a pair of support means one being on each side of the frame structure adjacent the driving wheel on such side, each of said support means mounting one of said motor means thereon, means pivotally connecting said support means on the frame structure at least partially within the space defined by the frame structure, each of said support means including control means for controlling the position of said support means about its pivotal connection to said frame, whereby each of said drive drums engages independently the associated driving wheel upon movement of said support means to a first position and diseugages the same upon movement of said support means to a second position for manual propulsion of the chair, a battery, carrying means for said battery carried by the frame structure, and power supply means for coupling said pair of motor means to said battery, said power supply means including a control box having first and second switches for each of said motor means, each of said first switches energizing the associated motor means for forward rotation and each of said second switches energizing the same for reverse rotation, said control box including supporting means for said switches with said first switches positioned forwardly thereon and said second switches positioned rearwardly thereon, said first switch associated with said right driving wheel being positioned to the left of said first switch associated with said left driving wheel and said second switch associated with the right driving wheel being positioned to the right of said second switch associated with the left driving wheel, so that simultaneous operation of the pair of said switch means in the forward positions and of the pair of switch means in the rearward positions energizes said motor means to rotate the same in the same rotational directions for forward and backward movement of the chair respectively, and simultaneous operation of said switches on the right and simultaneous operation of the switches on the left energizes said motor means for operation in different rotational directions to turn the wheel chair to the right and the left respectively.

9. A motorized propelling device for attachment to a wheel chair of the folding type having a frame structure for supporting a person with first and second sides formed of frame members and connected for movement toward each other to permit folding the chair, and which includes a pair of driving wheels mounted independently of one another on opposite sides of the frame structure, said device including in combination, a pair of reversible electric motor means individually associated with the driving wheels and each having a drive drum rotatable thereby and lying in a common plane with the corresponding driving wheel, a pair of support means one being on each side of the frame structure adjacent the driving wheel on such side, each of said support means mounting one of said motor means thereon, means pivotally connecting said support means on the frame structure at least partially within the space defined by the frame members on the sides of the chair, each of said support means including control means for controlling the position of said support means about its pivotal connection to said frame, whereby each of said drive drums engages individually the associated driving wheel upon operation of the associated control means to move the corresponding support means to a first position and disengages the same upon operation of the control means to move the corresponding support means to a second position for manual propulsion of the chair, a battery, carrying means for said battery removably carried by said frame structure, and a power supply circuit for coupling said pair of motor means to said battery, said power supply circuit including switch means for sup-- plying power to each of said motor means independently to cause rotation of the respective drive drums in forward and reverse directions, whereby the wheel chair may be driven in a straight line by the rotation. of said drive drums in the same rotational directions respectively and may be turned by the selected rotation of said drive drums.

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